(1) Field of the Invention:
The present invention relates to an apparatus for playing a disc stored in a cartridge.
(2) Description of the Prior Art:
There have recently been developed apparatus for playing discs while they are being rotatably stored in flat cartridges, respectively, for protection purpose. FIGS. 1 and 2 of the accompanying drawings illustrate such a conventional apparatus for playing a cartridge-stored disc.
As shown in FIG. 1, the apparatus has a housing 1 in which a flat support member 2 is disposed at a lower position. The support member 2 supports thereon a playback means including a turntable and a pickup. A guide plate 3 in the form a rectangular plate is fixed to a side end of the support member 2. The terms "lefthand" and "righthand" used below indicate directions as viewed in the direction of the arrow Y, and the term "upward" indicates the direction of the arrow Z. The support member 2 is position to extend in the direction of the arrow Y.
A cartridge holder 4 is disposed upwardly of the support member 2 for holding a flat cartridge 6 in which a disc 5 is rotatably supported. The cartridge 6 can be inserted through a loading/unloading slot la defined in the front panel of the housing 1 so that the cartridge 6 can be held by the cartridge holder 4.
A cam member 7 in the form of a rectangular plate is reciprocally mounted on the outer side of the guide plate 3 for back-and-forth movement in the direction of the arrow Y and the direction opposite thereto. The cam member 7 can be driven by a driving force applied by a driving force applying means (not shown).
The cartridge holder 4 has a plurality of legs 4a on which respective pins 4b project, respectively. The pins 4b slidably engage in respective guide slots 3b defined in the guide plate 3 and extending vertically in the direction of the arrow Z and the direction opposite thereto for guiding the cartridge holder 4 vertically. The pins 4b project outwardly from the respective guide slots 3b and also slidably engage in respective cam slots 7a defined in the cam member 7. The cam slots 7a are shaped such that when the cam member 7 is reciprocally moved, the cartridge holder 4 is moved vertically. More specifically, as shown in FIG. 4, when the cam member 7 is moved back in the direction opposite to the direction of the arrow Y, the cartridge holder 4 is guided by the guide plate 3 so as to be lowered for thereby placing the cartridge 6 held by the cartridge holder 4 onto the playback means on the support member 2.
Operation of the aforesaid apparatus for playing a cartridge-stored disc will be described below.
First, the cartridge 6 is inserted through the loading/unloading slot la into the housing 1 by the user until it is held by the cartridge holder 4. When the cartridge 6 held by the cartridge holder 4 is detected by a detector (not shown), the support member 2 is moved back in the direction opposite to the direction Y to the position shown in FIG. 1. Arrival of the support member 2 at the rear end of its stroke of movement is detected by another detctor (not shown), whereupon the cam member 7 is then moved back. The cartridge holder 4 is therefore lowered by being guided by the guide slots 3b of the guide plate 3 into the position of FIG. 2. The cartridge 6 is therefore placed on the playback means, which starts playing the disc in the cartridge 6. After the playback operation, the cartridge 6 is moved up and forwardly in the process which is a reversal of the above loading process until the front end of the cartridge 6 projects a certain distance from the loading/unloading slot 1a. The user can now hold the cartridge 6 for retrieval.
In the conventional apparatus for playing a cartridge-stored disc as described above, the pins 4b engaging in the cam slots 7a double as guide pins engaging the guide pins 3b, and the guide plate 3 which is flat and relatively large is required. Therefore, the apparatus is comparatively large in size. Since the guide plate 3 and its guide slots 36b are formed by pressing, the accuracy of their dimensions and positions cannot be inceased substantially, and the cartridge 6 cannot be positioned highly accurately with respect to the turntable.